Rhythmic Expression of timeless: A Basis for Promoting Circadian Cycles in period Gene Autoregulation

@article{Sehgal1995RhythmicEO,
  title={Rhythmic Expression of timeless: A Basis for Promoting Circadian Cycles in period Gene Autoregulation},
  author={Amita Sehgal and Adrian Rothenfluh-Hilfiker and Melissa Hunter-Ensor and Yifeng Chen and Michael P. Myers and Michael W. Young},
  journal={Science},
  year={1995},
  volume={270},
  pages={808 - 810}
}
The clock gene timeless (tim) is required for circadian rhythmicity in Drosophila. The accumulation of tim RNA followed a circadian rhythm, and the phase and period of the tim RNA rhythm were indistinguishable from those that have been reported for per. The tim RNA oscillations were found to be dependent on the presence of PER and TIM proteins, which demonstrates feedback control of tim by a mechanism previously shown to regulate per expression. The cyclic expression of tim appears to dictate… 
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TLDR
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TLDR
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TLDR
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TLDR
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The data indicate that regulation of PER nuclear entry is critical for circadian oscillations by providing a necessary temporal delay between PER synthesis and its effect on transcription.
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TLDR
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TLDR
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TLDR
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TLDR
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TLDR
Cycling of PER in brain cells of flies carrying the same 7.2 kb piece of per DNA under the control of a heat shock promoter corroborated the hypothesis that per's molecular cyclings and behavioral rhythmicity are causally related.
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